Q. Simplify the expression to a + bi form:(−5−9i)2Answer:
Apply Formula: To simplify the expression (−5−9i)2, we need to square the complex number (−5−9i). This involves using the formula (a−bi)2=a2−2abi+(bi)2.
Square Real Part: First, we square the real part: (−5)2=25.
Square Imaginary Part: Next, we square the imaginary part: (−9i)2. Remembering that i2=−1, we get (−9i)2=81i2=81(−1)=−81.
Calculate Middle Term: Now, we calculate the middle term, which is 2 times the product of the real part and the imaginary part: 2×(−5)×(−9i)=90i.
Combine Terms: We combine all the terms to get the simplified expression: 25−81+90i=−56+90i.
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